Add 15/42 and 63/54, Solve 15/42 + 1 9/54 as a fraction

Add 15/42 and 63/54

1^st number: 15/42, 2^nd number: 1 9/54

15/42 + 63/54 is 32/21.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 54 is 378

Next, find the equivalent fraction of both fractional numbers with denominator 378
For the 1st fraction, since 42 × 9 = 378,
15/42 = 15 × 9/42 × 9 = 135/378
Likewise, for the 2nd fraction, since 54 × 7 = 378,
63/54 = 63 × 7/54 × 7 = 441/378
Add the two like fractions:
135/378 + 441/378 = 135 + 441/378 = 576/378
576/378 simplified gives 32/21
So, 15/42 + 63/54 = 32/21
In mixed form: 111/21

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad